The Food Supply Chain (FSC) can be made more efficient, resilient, and transparent by implementing industry 4.0 technologies. In this context, blockchain and the Internet of Things (IoT) become a panacea for several FSC problems. As a result of FSC complexity and their specific needs, the adoption of Blockchain integrated IoT (B-IoT) in FSC is challenging, and further investigation is required. Therefore, this study aims to explore the Critical Success Factors (CSFs) for the adoption B-IoT in FSC. To achieve this objective, a literature review is conducted to identify the CSFs of B-IoT adoption and then a grey Delphi is conducted on finalised CSFs. Ten CSFs finalised that faceplate for the adoption of B-IoT in FSC. Further, these CSFs were analysed through a grey Decision-Making Trial and Evaluation Laboratory (DEMATEL) to determine the importance and causal relationships among them. A grey DEMATEL analysis also categorised these factors into influencing and influenced groups. The findings showed that “top management support”, “knowledge management”, “technology hardware readiness”, “skilled personnel”, and “high investment” were the influencing factors that needed to be addressed for the effective adoption of B-IoT. The FSC partners could benefit from the findings of this study by focusing on high-priority CSFs. The causal relationship among CSFs also helps the managers achieve optimal utilisation of resources. Further, this study encourages the FSC stakeholders to adopt the B-IoT in their supply chain to improve their performance.